Project Summary The proposed project will examine emotional functioning in adolescents and young adults who are at heightened risk for imminently developing a psychotic disorder (i.e., ultra-high-risk [UHR] youth), focusing on interactions with their parental caregivers. While alterations in emotional functioning have been observed in individuals with psychosis and in UHR youth, the field has primarily focused on corroborative, self-report, and clinical interview-based measures, and as a result, currently has a limited understanding of how in-depth, dynamic interactions may play a pathogenic role. The proposal is notable in using two cutting-edge methodologies (i.e., automated coding of emotional behavior; linkage analyses to index synchrony between youth and caregivers) to code and analyze behavioral and physiological functioning data collected during parent-youth interactions in high-risk and control dyads. The first aim of the proposed research is to determine differences in emotional behavior using automated facial coding during interaction between UHR youth and caregivers compared to control youth and caregivers. This is important because past studies have documented blunted affect in UHR youth. However, affective blunting has rarely been examined in social contexts that carry high emotional significance, such as during youth-caregiver interactions and has never been examined using automated coding of facial expressions in UHR youth as well as their caregivers. The second aim is to determine differences in behavioral and physiological linkage during interaction between UHR youth and caregivers compared to control youth and caregivers. This is important because high levels of linkage (or synchrony) during negative interactions are thought to amplify negative emotional qualities. At the same time, behavioral and physiological linkage has never been examined during UHR youth-caregiver interactions. UHR youth show dysregulated physiological functioning already at resting state and this physiological dysregulation may become amplified during negative interactions with parental caregivers and may be further exacerbated by caregivers' heightened emotional reactivity, resulting in heightened physiological linkage between UHR youth and caregivers during negative interaction. The third aim is to explore unique contributions of automatically-coded emotional behavior and behavioral and physiological linkage during interaction between UHR youth and caregivers in predicting UHR youth symptoms (i.e., social functioning, mental health). This is of particular importance given the promise of both methodologies in providing added-value in predicting UHR youth symptomatology over and above existing measures of emotional functioning during youth-caregiver interactions collected and analyzed under the funded parent award (i.e., human-coded emotional behavior; individual measures of behavioral and physiological functioning in youth and caregivers). By delineating specific emotional qualities of UHR youth- caregiver interactions that put UHR youth further at risk, the proposed research will provide the foundation for identifying specific screening and treatment targets for larger studies with youth and caregivers.